The present invention relates to a communication device, a communication method, and a communication system. For example, the present invention may be applied to a communication device for requesting a response from an opposing communication device and waiting for a certain time period.
For example, a communication device constituting a sensor network is configured to carry out communication while saving electric power.
Examples of a technology for normally carrying out mutual data communication between a communication device at a transmission side and a communication device at a reception side include the following document.
Non Patent Literature 1: IEEE Standard 802.15.4. Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Low-Rate Wireless Personal Area Networks, 2003
Non Patent Literature 2: M. Buettner, G Yee, E. Anderson and R. Han, “X-MAC: A Short Preamble MAC Protocol For Duty-Circled Wireless Sensor Networks”, SenSys 2006
According to the technology described in Non Patent Literature 1, in the case where a communication device at a transmission side transmits a frame with a response request in processing of a media access layer (MAC layer), the communication device waits for a response acknowledgement (frame) from a communication device at a reception side for a response waiting time (macAckWaitDuration). When receiving the response, the communication device at the transmission side decides that the transmission has been normally completed. When there is no response, the communication device at the transmission side decides that the abnormality has occurred and retransmits the frame. The response waiting time is calculated from a time spent on switching a wireless unit from a reception state to a transmission state, an expected response frame length, and the like. As the response waiting time, an expected time period in which reception of the expected response frame is completed is set.
On the other hand, according to the technology described in Non Patent Literature 2, a communication device at a transmission side transmits a series of frames called short preambles before transmitting a data frame, and a communication device at a reception side which carries out intermittent reception transmits a response frame to the short preambles. Subsequently, the communication device at the transmission side transmits the data frame (see FIG. 1 in Non Patent Literature 2).